The overall aim of the Genetics Core is to provide cytogenetic and genetic characterization of program project participants for studies of aging and dementia in adults with Down syndrome and to provide cytogenetic characterization of animal subjects and brain tissue. This will include cytogenetic analyses of newly recruited adults with Down syndrome and of continuing participants who have not previously received cytogenetic confirmation of Trisomy 21. We will employ both standard karyotyping as well as nuclear fluorescence in situ hybridization (FISH) studies.